What is bigger four fifths or seventeen twentieths?

17/20 is larger than 4/5.

To compare fractions, put them both in a common denominator.

Here, you can multiply 4/5 by 4/4 (equality) to create the fraction 16/20.

17/20 > 16/20

You can create a common denominator for fractions (where one is not a factor of the other) by finding the Least Common Multiple : multiply their uncommon factors by their common factors.

Here, 20 is already a multiple of 5.